Pheynl or benzyl-substituted rolipram-based compounds for and method of inhibiting phosphodiesterase IV

ABSTRACT

Rolipram-based PDE IV inhibitors containing phenyl- or benzyl-substituted moieties of the formula: ##STR1## wherein X 1  and X 2  may be the same or different and each is O or S; 
     R 1  is selected from the group consisting of hydrogen, saturated or unsaturated straight-chain or branched C 2-12  alkyl groups, cycloalkyl and cycloalkyl-alkyl groups containing from 3 to 10 carbon atoms in the cycloalkyl moiety; 
     R 2  =R 1  or --CH 3  ; 
     R 3  is hydrogen, halogen, or a saturated or unsaturated straight-chain or branched C 1-12  alkyl group, a cycloalkyl or cycloalkyl-alkyl groups containing from 3 to 7 carbon atoms in the cycloalkyl moiety; 
     Z is a linkage selected from --CH 2  CONH-- or --CH 2  NHCO--, and 
     R 4  is a phenyl or benzyl which may be unsubstituted or substituted with one or more halogen atoms, alkyl groups, hydroxyl groups, cyano groups, carboxyl groups, alkoxy groups, alkoxycarbonyl, amido, carboxamido, substituted or unsubstituted amino groups, cycloalkyl and cycloalkyl-alkyl groups containing from 3 to 10 carbon atoms in the cycloalkyl moiety, aryl or aralkyl groups preferably containing from about 6 to about 10 carbon atoms, or heterocyclic groups containing nitrogen, oxygen or sulfur in the ring; the alkyl, alkoxy, cycloalkyl, cycloalkylalkyl, aryl, and aryl-alkyl groups being saturated or unsaturated, unsubstituted or substituted by halogen atoms, hydroxyl groups, cyano groups, carboxyl groups, alkoxy groups, alkoxycarbonyl, carboxamido or substituted or unsubstituted amino groups, or one or more lower alkyl groups having from 1 to 3 carbon atoms; 
     provided that R 4  cannot be substituted with more than one methoxy group. compared to theophylline or rolipram as well as with improved selectivity with regard to PDE III inhibition. Pharmaceutical compositions containing the same and methods of treatment are also disclosed.

This application is a continuation-in-part of U.S. patent applicationSer. No. 08/265,641 filed Jun. 24, 1994.

BACKGROUND OF THE INVENTION

Asthma is a complex disease involving the concerted actions of multipleinflammatory and immune cells, spasmogens, inflammatory mediators,cytokines and growth factors. In recent practice there have been fourmajor classes of compounds used in the treatment of asthma, namelybronchodilators (e.g., β-adrenoceptor agonists), anti-inflammatoryagents (e.g., corticosteroids), prophylactic anti-allergic agents (e.g.,cromolyn sodium) and xanthines (e.g., theophylline) which appear topossess both bronchodilating and anti-inflammatory activity.

Theophylline has been a preferred drug of first choice in the treatmentof asthma. Although it has been touted for its direct bronchodilatoryaction, theophylline's therapeutic value is now believed to also stemfrom anti-inflammatory activity. Its mechanism of action remainsunclear. However, it is believed that several of its cellular activitiesare important in its activity as an anti-asthmatic, including cyclicnucleotide phosphodiesterase inhibition, adenosine receptor antagonism,stimulation of catecholamine release, and its ability to increase thenumber and activity of suppressor T-lymphocytes. While all of theseactually may contribute to its activity, only PDE inhibition may accountfor both the anti-inflammatory and bronchodilatory components. However,theophylline is known to have a narrow therapeutic index, and a widerange of untoward side effects which are considered problematic.

Of the activities mentioned above, theophylline's activity in inhibitingcyclic nucleotide phosphodiesterase has received considerable attentionrecently. Cyclic nucleotide phosphodiesterases (PDEs) have receivedconsiderable attention as molecular targets for anti-asthmatic agents.Cyclic 3',5'-adenosine monophosphate (cAMP) and cyclic 3',5'-guanosinemonophosphate (cGMP) are known second messengers that mediate thefunctional responses of cells to a multitude of hormones,neurotransmitters and autocoids. At least two therapeutically importanteffects could result from phosphodiesterase inhibition, and theconsequent rise in intracellular adenosine 3',5'-monophosphate (cAMP) orguanosine 3',5'-monophosphate (cGMP) in key cells in the pathophysiologyof asthma. These are smooth muscle relaxation (resulting inbronchodilation) and anti-inflammatory activity.

It has become known that there are multiple, distinct PDE isoenzymeswhich differ in their cellular distribution. A variety of inhibitorspossessing a marked degree of selectivity for one isoenzyme or the otherhave been synthesized.

The structure-activity relationships (SAR) of isozyme-selectiveinhibitors has been discussed in detail, e.g., in the article ofTheodore J. Torphy, et al , "Novel Phosphodiesterase Inhibitors For TheTherapy Of Asthma", Drug News & Prospectives, 6(4) May 1993, pages203-214. The PDE enzymes can be grouped into five families according totheir specificity toward hydrolysis of cAMP or cGMP, their sensitivityto regulation by calcium, calmodulin or cGMP, and their selectiveinhibition by various compounds. PDE I is stimulated by Ca²⁺/calmodulin. PDE II is cGMP-stimulated, and is found in the heart andadrenals. PDE III is cGMP-inhibited, and inhibition of this enzymecreates positive inotropic activity. PDE IV is cAMP specific, and itsinhibition causes airway relaxation, anti-inflammatory andant-depressant activity. PDE V appears to be important in regulatingcGMP content in vascular smooth muscle, and therefore PDE V inhibitorsmay have cardiovascular activity.

While there are compounds derived from numerous structure activityrelationship studies which provide PDE III inhibition, the number ofstructural classes of PDE IV inhibitors is relatively limited. Analoguesof rolipram, which has the following structural formula: ##STR2## and ofRO-20-1724, which has the following structural formula: ##STR3## havebeen studied.

Rolipram, which was initially studied because of its activity as anantidepressant has been shown to selectively inhibit the PDE IV enzymeand this compound has since become a standard agent in theclassification of PDE enzyme subtypes. There appears to be considerabletherapeutic potential for PDE IV inhibitors. Besides initial worksuggesting an anti-depressive action, rolipram has been investigated forits anti-inflammatory effects, particularly in asthma. In-vitro,rolipram, RO20-1724 and other PDE IV inhibitors have been shown toinhibit (1) mediator synthesis/release in mast cells, basophils,monocytes and eosinophils; (2) respiratory burst, chemotaxis anddegranulation in neutrophils and eosinophils; and (3) mitogen-dependentgrowth and differentiation in lymphocytes (The PDE IV Family OfCalcium-Phosphodiesterases Enzymes, John A. Lowe, III, et al., Drugs ofthe Future 1992, 17(9):799-807).

PDE IV is present in all the major inflammatory cells in asthmaincluding eosinophils, neutrophils, T-lymphocytes, macrophages andendothelial cells. Its inhibition causes down-regulation of cellularactivation and relaxes smooth muscle cells in the trachea and bronchus.On the other hand, inhibition of PDE III, which is present inmyocardium, causes an increase in both the force and rate of cardiaccontractility. These are undesirable side effects for ananti-inflammatory agent. Theophylline, a nonselective PDE inhibitor,inhibits both PDE III and PDE IV, resulting in both desirableanti-asthmatic effects and undesirable cardiovascular stimulation. Withthis well-known distinction between PDE isozymes, the opportunity forconcomitant anti-inflammation and bronchodilation without many of theside effects associated with theophylline therapy is apparent. Theincreased incidence of morbidity and mortality due to asthma in manyWestern countries over the last decade has focused the clinical emphasison the inflammatory nature of this disease and the benefit of inhaledsteroids. Development of an agent that possesses both bronchodilatoryand anti-inflammatory properties would be most advantageous.

It appears that selective PDE IV inhibitors should be more effectivewith fewer side effects than theophylline.

Attempts have therefore been made to find new compounds having moreselective and improved PDE IV inhibition.

OBJECTS AND SUMMARY OF THE INVENTION

It is accordingly a primary object of the present invention to providenew compounds which are effective PDE IV inhibitors.

It is another object of the present invention to provide new compoundswhich act as effective PDE IV inhibitors with lower PDE III inhibition.

It is a further object of the present invention to provide new compoundswhich have a superior PDE IV inhibitory effect as compared totheophylline or other known compounds.

It is a further object of the present invention to provide new compoundswhich have a substantially equal or superior PDE IV inhibitory effect ascompared to known chemical compounds, and which exhibit surprisinglygreater selectivity with regard to their inhibitory effects.

It is another object of the present invention to provide a method oftreating a patient requiring PDE IV inhibition.

It is another object of the present invention to provide new compoundsfor treating disease states associated with abnormally highphysiological levels of cytokines, including tumor necrosis factor.

It is another object of the present invention to provide a method ofsynthesizing the new compounds of this invention.

It is another object of the present invention to provide a method fortreating a mammal suffering from a disease state selected from the groupconsisting of asthma, arthritis, allergies, inflammation, depression,dementia and disease states associated with abnormally highphysiological levels of cytokines.

With the above and other objects in view, the present invention mainlycomprises a compound of the formula: ##STR4## wherein: X₁ and X₂ may bethe same or different and each is O or S;

R₁ and R₂ may be the same or different and each is selected from thegroup consisting of hydrogen, saturated or unsaturated straight-chain orbranched C₁₋₁₂ alkyl groups, cycloalkyl and cycloalkyl-alkyl groupscontaining from 3 to 10 carbon atoms in the cycloalkyl moiety;

R₃ is hydrogen, halogen, or a saturated or unsaturated straight-chain orbranched C₁₋₁₂ alkyl group, a cycloalkyl and cycloalkyl-alkyl groupscontaining from 3 to 7 carbon atoms in the cycloalkyl moiety;

Z is a linkage selected from --NHCH₂ --, --CH₂ NH--, --CH₂ CONH--, --CH₂NHCO--, --CH₂ CO--, --COCH₂ --, --CH₂ COCH₂ --, --C(═NQ)NH-- andC(═NOCONHQ)--;

R₄ is a phenyl or benzyl or a 6-membered heteroaryl group which may beunsubstituted or substituted with one or more halogen atoms, alkylgroups, hydroxyl groups, cyano groups, nitro groups, carboxyl groups,alkoxy groups, alkoxycarbonyl, amido, carboxamido, substituted orunsubstituted amino groups, cycloalkyl and cycloalkyl-alkyl groupscontaining from 3 to 10 carbon atoms in the cycloalkyl moiety, aryl oraralkyl groups preferably containing from about 6 to about 10 carbonatoms, or heterocyclic groups containing nitrogen, oxygen or sulfur inthe ring; said alkyl, cycloalkyl, cycloalkyl-alkyl, aryl, and aryl-alkylgroups being unsubstituted or substituted by halogen atoms, hydroxylgroups, cyano groups, carboxyl groups, alkoxy groups, alkoxycarbonyl,carboxamido or substituted or unsubstituted amino groups, or one or morelower alkyl groups having from 1 to 3 carbon atoms;

Q is R₄ or hydrogen;

except that when Z═--C(═NOCONHQ)--, R₄ is not benzyl; and R₁ and R₂ areboth not hydrogen.

The term "lower alkyl" is defined for purposes of the present inventionas straight or branched chain radicals having from 1 to 3 carbon atoms.

DETAILED DESCRIPTION

The compounds of the present invention, as demonstrated in the appendedexamples, are effective in the mediation or inhibition of PDE IV inhumans and other mammals. Further, these compounds are selective PDE IVinhibitors which possess both bronchodilatory and anti-inflammatoryproperties substantially without undesirable cardiovascular stimulationcaused by PDE III inhibition. Many of these compounds have asubstantially equal or superior PDE IV inhibitory effect as compared totheophylline.

The present invention is further related to a method for the treatmentof allergic and inflammatory disease which comprises administering to amammal in need thereof an effective amount of the compounds of thepresent invention.

The present invention is also related to a method for the mediation orinhibition of the enzymatic or catalytic activity of PDE IV activity inmammals, particularly humans, which comprises administering an effectiveamount of the above-described compounds of the invention to a mammal inneed of PDE IV inhibition.

The compounds of the present invention may find use in the treatment ofother disease states in humans and other mammals, such as in thetreatment of disease states associated with a physiologicallydetrimental excess of tumor necrosis factor (TNF). TNF activatesmonocytes, macrophages and T-lymphocytes. This activation has beenimplicated in the progression of Human Immunodeficiency Virus (HIV)infection and other disease states related to the production of TNF andother cytokines modulated by TNF.

In certain preferred embodiments, the compounds of the present inventioncomprise the formula: ##STR5## wherein: X₁ and X₂ may be the same ordifferent and each is O or S; and R₁ and R₂ may be the same or differentand each is selected from the group consisting of hydrogen, saturated orunsaturated straight-chain or branched C₁₋₁₂ alkyl groups, cycloalkyland cycloalkyl-alkyl groups containing from 3 to 10 carbon atoms in thecycloalkyl moiety;

R₃ is hydrogen, halogen, or a saturated or unsaturated straight-chain orbranched C₁₋₁₂ alkyl group, a cycloalkyl and cycloalkyl-alkyl groupscontaining from 3 to 7 carbon atoms in the cycloalkyl moiety;

Z is a linkage selected from --NHCH₂ --, --CH₂ NH--, --CH₂ CONH--, --CH₂NHCO--, --CH₂ CO--, --COCH₂ --, --CH₂ COCH₂ --, --C(═NQ)NH-- andC(═NOCONHQ)--;

R₄ is a phenyl or benzyl or a 6-membered heteroaryl group which may beunsubstituted or substituted with one or more halogen atoms, alkylgroups, hydroxyl groups, cyano groups, nitro groups, carboxyl groups,alkoxy groups, alkoxycarbonyl, amido, carboxamido, substituted orunsubstituted amino groups, cycloalkyl and cycloalkyl-alkyl groupscontaining from 3 to 10 carbon atoms in the cycloalkyl moiety, aryl oraralkyl groups preferably containing from about 6 to about 10 carbonatoms, or heterocyclic groups containing nitrogen, oxygen or sulfur inthe ring; said alkyl, cycloalkyl, cycloalkyl-alkyl, aryl, and aryl-alkylgroups being unsubstituted or substituted by halogen atoms, hydroxylgroups, cyano groups, carboxyl groups, alkoxy groups, alkoxycarbonyl,carboxamido or substituted or unsubstituted amino groups, or one or morelower alkyl groups having from 1 to 3 carbon atoms;

Q is R₄ or hydrogen;

except that when Z═--C(═NOCONHQ)--, R₄ is not benzyl; and R₁ and R₂ areboth not hydrogen.

In certain preferred embodiments, R₄ is a phenyl or substituted phenylhaving one of the structures: ##STR6## wherein R₆ is a substituted orunsubstituted lower alkyl having from about 1 to about 3 carbon atoms.

In another preferred embodiment R₄ is one of the following heteroarylgroups having the structure: ##STR7##

In further preferred embodiments, Z is a linkage NHCO--, --COCH₂ --,--CH₂ CO--, --C(═NQ)NH-- and --C(═NOCONHQ)--.

Certain preferred compounds of the present invention include:

(I)N-(3-Cyclopentyloxy-4-methoxyphenyl-acetyl)-2-allyloxy-5-chloroaniline;

(II)N-(3-Cyclopentyloxy-4-methoxyphenyl-acetyl)-2-hydroxy-3-allyl-5-chloroaniline;

(III)1-(3-Cyclopentyloxy-4-methoxyphenyl)phenone-O-(aminocarbonyl)oxime;

(IV)1-(3-cyclopentyloxy-4-methoxyphenyl)-(2-(5-(pyrimid-2,4-dionyl)))ethanone;and

(V)N-Benzyl-N'-(3,5-dichloropyrid-4-yl)-3-cyclopentyloxy-4-methoxybenzamidine.

Representative processes for preparing the compounds of the presentinvention are shown below:

Detailed description of several syntheses are shown in the Examples.##STR8##

The compounds of the present invention have been found to be highlyeffective PDE IV inhibitors, the inhibition of which is in factsignificantly and surprisingly greater than that of theophylline. Theconcentration which yields 50% inhibition of PDE IV (IC₅₀) for thecompound prepared in Example 5 is 0.3 μM, whereas the IC₅₀ for rolipramwhen run in the same assay was 2.8 μM. It is apparent that thisinventive compound is several times as effective as a PDE IV inhibitoras compared to rolipram (or theophylline).

Since the PDE III IC₅₀ of an Example 5 compound is >1000 uM, it is clearthat the compound of the invention is highly selective as a PDE IVinhibitor.

Accordingly, the compounds of the present invention can be administeredto anyone requiring PDE IV inhibition. Administration may be orally,topically, by suppository, inhalation or insufflation, or parenterally.

The present invention also encompasses all pharmaceutically acceptablesalts of the foregoing compounds. One skilled in the art will recognizethat acid addition salts of the presently claimed compounds may beprepared by reaction of the compounds with the appropriate acid via avariety of known methods. Alternatively, alkali and alkaline earth metalsalts are prepared by reaction of the compounds of the invention withthe appropriate base via a variety of known methods. For example, thesodium salt of the compounds of the invention can be prepared viareacting the compound with sodium hydride.

Various oral dosage forms can be used, including such solid forms astablets, gelcaps, capsules, caplets, granules, lozenges and bulk powdersand liquid forms such as emulsions, solution and suspensions. Thecompounds of the present invention can be administered alone or can becombined with various pharmaceutically acceptable carriers andexcipients known to those skilled in the art, including but not limitedto diluents, suspending agents, solubilizers, binders, disintegrants,preservatives, coloring agents, lubricants and the like.

When the compounds of the present invention are incorporated into oraltablets, such tablets can be compressed, tablet triturates,enteric*coated, sugar*coated, film*coated, multiply compressed ormultiply layered. Liquid oral dosage forms include aqueous andnonaqueous solutions, emulsions, suspensions, and solutions and/orsuspensions reconstituted from non*effervescent granules, containingsuitable solvents, preservatives, emulsifying agents, suspending agents,diluents, sweeteners, coloring agents, and flavorings agents. When thecompounds of the present invention are to be injected parenterally, theymay be, e.g., in the form of an isotonic sterile solution.Alternatively, when the compounds of the present invention are to beinhaled, they may be formulated into a dry aerosol or may be formulatedinto an aqueous or partially aqueous solution.

In addition, when the compounds of the present invention areincorporated into oral dosage forms, it is contemplated that such dosageforms may provide an immediate release of the compound in thegastrointestinal tract, or alternatively may provide a controlled and/orsustained release through the gastrointestinal tract. A wide variety ofcontrolled and/or sustained release formulations are well known to thoseskilled in the art, and are contemplated for use in connection with theformulations of the present invention. The controlled and/or sustainedrelease may be provided by, e.g., a coating on the oral dosage form orby incorporating the compound(s) of the invention into a controlledand/or sustained release matrix.

Specific examples of pharmaceutically acceptable carriers and excipientsthat may be used for formulate oral dosage forms, are described in theHandbook of Pharmaceutical Excipients, American PharmaceuticalAssociation (1986), incorporated by reference herein. Techniques andcompositions for making solid oral dosage forms are described inPharmaceutical Dosage Forms: Tablets (Lieberman, Lachman and Schwartz,editors) 2nd edition, published by Marcel Dekker, Inc., incorporated byreference herein. Techniques and compositions for making tablets(compressed and molded), capsules (hard and soft gelatin) and pills arealso described in Remington's Pharmaceutical Sciences (Arthur Osol,editor), 1553*1593 (1980), incorporated herein by reference. Techniquesand composition for making liquid oral dosage forms are described inPharmaceutical Dosage Forms: Disperse Systems, (Lieberman, Rieger andBanker, editors) published by Marcel Dekker, Inc., incorporated hereinby reference.

When the compounds of the present invention are incorporated forparenteral administration by injection (e.g., continuous infusion orbolus injection), the formulation for parenteral administration may bein the form of suspensions, solutions, emulsions in oily or aqueousvehicles, and such formulations may further comprise pharmaceuticallynecessary additives such as stabilizing agents, suspending agents,dispersing agents, sustained release agents, and the like. The compoundsof the invention may also be in the form of a powder for reconstitutionas an injectable formulation.

The dose of the compounds of the present invention is dependent upon theaffliction to be treated, the severity of the symptoms, the route ofadministration, the frequency of the dosage interval, the presence ofany deleterious side-effects, and the particular compound utilized,among other things.

The PDE IV inhibitory compounds of the present invention may be examinedfor their PDE IV inhibitory effects via the techniques set forth in thefollowing examples, wherein the ability of the compounds to inhibit PDEIV isolated from bovine tracheal smooth muscle is set forth.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following examples illustrate various aspects of the presentinvention, and are not to be construed to limit the claims in any mannerwhatsoever.

EXAMPLE 1 Preparation ofN-(3-Cyclopentyloxy-4-methoxyphenyl-acetyl)-2-allyloxy-5-chloroaniline

a) 3-Cyclopentyloxy-4-methoxybenzyl alcohol

A solution of 3-cyclopentyloxy-4-methoxybenzaldehyde (38 grams, 0.17mol) in 40 milliliters of ethanol and sodium borohydride (1.63grams,0.043 mol) was stirred for 2 hours at room temperature untilcomplete by TLC. The reaction was diluted with water and extracted withethyl acetate. Evaporation of the ethyl acetate afforded3-cyclopentyloxy-4-methoxybenzyl alcohol (37 grams, 98%) suitable forthe next step.

b) 3-Cyclopentyloxy-4-methoxybenzyl chloride

A solution containing 3-cyclopentyloxy-4-methoxybenzyl alcohol (112grams, 0.50 mol), prepared as described in step a), in 1 liter ofmethylene chloride was stirred at room temperature with concentrated HCl(110 milliliters, 1.2 mol) for 3 hours, at which time the reaction wasdone by TLC. The layers were separated and the methylene chloridesolution was washed twice with water and evaporated under reducedpressure to give 3-cyclopentyloxy-4-methoxybenzyl chloride (119 grams,100%).

c) 3-Cyclopentyloxy-4-methoxyphenylacetonitrile

A mixture of 3-cyclopentyloxy-4-methoxybenzyl chloride (119 grams, 0.49mol), 120 milliliters of methylene chloride, KCN (70.7 grams, 1.09 mol),benzyltriethylammonium chloride (35 grams, 0.015 mol) and water (120milliliters) was stirred vigorously at room temperature for 48 hours.The reaction mixture was diluted with methylene chloride and the layerswere separated. The methylene chloride solution was extracted severaltimes with water and evaporated to yield3-cyclopentyloxy-4-methoxyphenylacetonitrile (109 grams, 95%) for thesubsequent transformation.

d) 3-Cyclopentyloxy-4-methoxyphenylacetic acid

A solution of 3-cyclopentyloxy-4-methoxyphenylacetonitrile (109 grams,0.43 mol) in 1330 milliliters of ethanol and NaOH (51 grams, 1.3 mol)was heated under reflux for 48 hours. Ethanol (500 milliliters) wasdistilled from the reaction mixture and the residue was diluted withwater and stirred with Norit A (11 grams) for 2 minutes. The mixture wasfiltered through a pad of celite and acidified to pH 1 with concentratedHCl. Extraction of the mixture with diethyl ether yielded 120 grams ofcrude 3- cyclopentyloxy-4-methoxy-phenylacetic acid after evaporation ofthe ether at reduced pressure. The crude acid was dissolved in warmtoluene (400 milliliters) and stirred for 1 hour with 10.5 grams ofNorit A. The charcoal was filtered and the toluene solution was dilutedwith heptane (40 milliliters). Filtration of the cooled solutionafforded 72 grams (67%) of pure 3-cyclopentyloxy-4-methoxyphenylaceticacid, mp 79°-80°.

e) N-(3-Cyclopentyloxy-4-methoxy-phenylacetyl)-2-hydroxy-5-chloroaniline

A solution of 3-cyclopentyloxy-4-methoxyphenylacetic acid (10 grams,0.040 mol) in 20 milliliters of methylene chloride was added dropwise toa stirred slurry of 1,1'-carbonyldiimidazole (7.1 grams, 0.044 mol) in40 milliliters of methylene chloride. After stirring for 2 hours, theresulting solution was added to a solution of 2-hydroxy-5-chloraniline(6.0 grams, 0.042 mol) in methylene chloride (75 milliliters). Afterstirring overnight, water was added and stirring was continued. Thelayers were separated and the methylene chloride layer was washed with100 milliliter portions of water, dilute aqueous HCl, and water.Evaporation of the methylene chloride afforded the solid amide which wastriturated with methanol (20 milliliter) and filtered to give 10.7 grams(71%) ofN-(3-cyclopentyloxy-4-methoxyphenylacetyl)-2-hydroxy-5-chloraniline, mp151°-152°.

f)N-(3-Cyclopentyloxy-4-methoxyphenyl-acetyl)-2-allyloxy-5-chloroaniline

In this step, allyl chloride (23.3 grams, 0.31 mol) was added to astirred solution ofN-(3-cyclopentyloxy-4-methoxyphenylacetyl)-2-hydroxy-5-chloroaniline (78grams, 0.21 mol) in ethanol (600 millilters) and 1N NaOH in methanol(213 milliters). The mixture was heated under reflux for 8 hours andthen diluted with water and extracted twice with ethyl acetate.Evaporation of the ethyl acetate and crystallization of the residue frommethanol gave 56.4 grams (65%) of the title compound, mp 75°-76.5°.

EXAMPLE 2 Preparation ofN-(3-Cyclopentyloxy-4-methoxyphenyl-acetyl)-2-hydroxy-3-allyl-5-chloroaniline

A solution ofN-(3-cyclopentyloxy-4-methoxyphenylacetyl)-2-allyloxy-5-chloroaniline(33 grams, 0.079 mol) in 330 milliliters of diphenyl ether was heated at180° for 6.5 hours. This reaction mixture was combined with a secondreaction mixture containingN-(3-cyclopentyloxy-4-methoxyphenylacetyl)-2-allyloxy-5-chloroanilineand 250 milliliters of diphenyl ether which had been heated at 180° for20 hours.

The combined reaction mixtures were diluted with 800 milliliters ofhexane and applied to a flash chromatography column prepared from 470grams of flash chromatography silica gel. Fractions of 800 milliliterswere collected. Fractions 1-6 (hexane) contained only diphenyl ether.Fraction 7 (1:1 hexane/methylene chloride) contained 1 gram of material.Fractions 8-11 (methylene chloride) contained 34.5 grams of materialwith a higher R_(f) on TLC (2% methanol/methylene chloride, silica gel)than the title compound. Fractions 12-17 (methylene chloride) gave 20grams (34%) of the crude title compound. A sample of this material (1.0grams) was recrystallized from 10 milliliters of ethanol to give thepure title compound, mp 119°-120°.

EXAMPLE 3 Preparation of1-(3-Cyclopentyloxy-4-methoxyphenyl)phenone-O-(aminocarbonyl)oxime

a) α-Phenyl-3-cyclopentyloxy-4-methoxybenzyl alcohol

Phenyllithium (1.8M solution in cyclohexane/diethyl ether, 25.5milliliters, 46 mmol) was added dropwise over 15 minutes to a stirredsolution of 3-cyclopentyloxy-4-methoxybenz-aldehyde (6 grams, 27 mmol)in dry tetrahydrofuran (20 milliliters) at -78° C. The resultingsolution was stirred at -78° C. for 30 minutes and quenched at -78° C.by the rapid addition of aqueous saturated NH₄ Cl (70 milliliters).After warming to room temperature, water was added to dissolve thesolids and volatiles were removed in vacuo. The residue was partitionedbetween water (250 milliliters) and ethyl acetate (250 milliliters), theaqueous phase was extracted with ethyl acetate (3×250 milliliters) andthe combined organic layers washed with water (200 milliliters). Theorganics were dried over Na₂ SO₄ and concentrated in vacuo to give alight yellow oil. The oil was purified by flash chromatography (SiO₂:hexane/ethyl acetate (4:1)) to afford the title compound as a paleyellow oil (7.4 grams) .

¹ H NMR (CDCl₃,250 MHz) δ 7.30 (m, 5H), 6.84 (m,3H), 5.76 (s, 1H), 4.72(m, 1H), 3.81 (s, 3H), 2.26 (s, 1S), 1.85 (m, 6H), 1.59 (m, 2H).

b) 1-(3-Cyclopentyloxy-4-methoxyphenyl)phenone

Pyridinium dichromate (13.22 grams, 35.19 mmol) was added in one portionto a stirred solution of α-phenyl-3-cyclopentyloxy-4-methoxybenzylalcohol (7.0 grams, 23.5 mmol) in dry methylene chloride (200milliliters) at room temperature. The resulting heterogeneous solutionwas stirred at room temperature overnight. The reaction mixture wasdiluted with an equal volume of diethyl ether and stirred for 1 hour.The mixture was filtered through celite and the filter cake washed withdiethyl ether (150 milliliters) and ethyl acetate (150 milliliters). Thebrown filtrate was concentrated in vacuo and purified by flashchromatography (SiO₂ :hexane/ethyl acetate (7:3) to yield the titlecompound as an orange solid (6.940 grams).

¹ H NMR (CDCl₃,250 MHz) δ 7.75 (m, 2H), 7.46 (m,5H), 5.76 (s, 1H), 4.72(m, 1H), 3.81 (s, 3H), 2.26 (s, 1H), 1.85 (m, 6H), 1.59 (m, 2H).

c) 1-(3-Cyclopentyloxy-4-methoxyphenyl)phenone oxime

Hydroxylamine hydrochloride (1.179 grams, 25.7 mmol) was added in oneportion to a magnetically stirred solution of1-(3-cyclopentyloxy-4-methoxyphenyl)phenone (6.936 grams, 23.4 mmol) indry pyridine (120 milliliters) at room temperature. The resultingsuspension slowly became homogeneous and the solution was stirred atroom temperature overnight. Further hydroxylamine hydrochloride (0.5grams, 7.17 mmol) was added to the reaction mixture and stirringcontinued overnight. The pyridine was removed in vacuo and the residuepartitioned between ethyl acetate (200 milliliters) and water (200milliliters). The aqueous phase was extracted with ethyl acetate (2×125milliliters), the organics dried over Na₂ SO₄ and concentrated in vacuoto give an orange oil. The oil was purified by flash chromatography(SiO₂ :hexane/ethyl acetate (4:1)) to afford the title compound as a tansolid (2.49 grams).

R_(f) (SiO₂ :ethyl acetate/hexane (3:7)) 0.25.

d) 1-(3-Cyclopentyloxy-4-methoxy-phenyl)phenone-O-(aminocarbonyl)oxime

Anhydrous trifluoroacetic acid (2.45 milliliters, 3.64 grams, 31.92mmol) was addded dropwise over 10 minutes at room temperature to aslowly stirred suspension of sodium cyanate (4.15 grams, 63.84 mmol) inmethylene chloride (30 milliliters). The suspension slowly thickened toa gelatinous mass which was periodically agitated by hand. After 30minutes at room temperature, 1-(3-cyclopentyloxy-4-methoxyphenyl)phenoneoxime (2.49 grams, 7.99 mmol) in methylene chloride (10 milliliters) wasadded in one portion and the reaction mixture stirred under nitrogen for1 hour. The reaction mixture was poured into saturated NaHCO₃ (100milliliters) and extracted with methylene chloride (2×200 milliliters).The organic phase was washed with water (100 milliliters), dried (Na₂SO₄) and concentrated in vacuo to give a pale yellow oil. The oil waspurified by flash chromatography (SiO₂ :methylene chloride/ethyl acetate(9:1)) to yield the title compound as a white solid (1.21 grams). m.p.129°-132° C.

¹ H NMR (CDCl₃,250 MHz) δ 7.43 (m, 5H), 6.94 (m,3H), 4.69 (m, 1H), 3.86(3, 3H), 1.78 (m, 6H), 1.60 (m, 2H).

EXAMPLE 4 Preparation of1-(3-cyclopentyloxy-4-methoxyphenyl)-(2-(5-(pyrimid-2,4-dionyl)))ethanone

a) [[1-(3-Cyclopentyloxy-4-methoxyphenyl)-1-ethenyl]oxy]trimethylsilane

Lithium diisopropylamide (1.5M solution in cyclohexane, 12.5milliliters, 18.75 mmol) was added over 3 minutes to a stirred solutionof 3-cyclopentyloxy-4-methoxyacetophenone (3 grams, 12.8 mmol) in drytetrahydrofuran (10 milliliters) at -78° C. After the addition wascomplete, the solution was stirred for 30 minutes at -78° C. andtrimethylsilyl chloride (2.4 milliliters, 30.72 mmol) was added in oneportion. The mixture was allowed to warm to room temperature, stirredfor 20 minutes, and quenched with saturated NaHCO₃ (35 milliliters). Theresulting mixture was extracted with hexane (2×50 milliliters), theorganic layer dried (Na₂ SO₄) and the solvent removed in vacuo to affordthe title compound as a colorless oil (4 grams); 80% pure by gaschromatography/mass spectrometry.

b)1-(3-cyclopentyloxy-4-methoxyphenyl)-(2-(5-(pyrimid-2,4-dionyl)))ethanone

A stirred solution of([1-(3-cyclopentyloxy-4-methoxyphenyl)-1-ethenyl)oxy]trimethylsilane(4.0 grams, 80% pure by gas chromatography, 10.3 mmol), 5-bromouracil(1.73 grams, 9.14 mmol), tributyltin fluoride (2.8 grams, 9.14 mmol) andbis(triphenylphosphine)palladium (II) chloride (215 milligrams, 3.0×10⁻⁴mmol) in 1,4 dioxane (50 milliliters) was refluxed for 60 hours. Thereaction mixture was cooled to room temperature, diluted with diethylether (150 milliliters) and washed with 1N NaOH (3×60 milliliters). Theaqueous layer was neutralized with 12N HCl and extracted with methylenechloride (3×50 milliliters). The organics were dried (Na₂ SO₄) and thesolvent removed in vacuo to afford an oil. The oil was purified bychromatography on SiO₂ eluting with methylene chloride/ethanol/ammonia(9:1:0.1) to yield the title compound as a white solid (70 milligrams).

¹ H NMR (CDCl₃ ;250 MHz) δ 9.28 (brs, 1H), 8.87 (brs, 1H), 7.16 (s, 1H),6.84 (m, 3H), 5.69 (s, 1H), 5.46 (s, 1H), 4.75 (m, 1H), 3.83 (s, 3H),1.81 (m, 6H), 1.57 (m, 2H).

EXAMPLE 5N-Benzyl-N'-(3,5-dichloropyrid-4-yl)-3-cyclopentyloxy-4-methoxybenzamidine

A solution ofN-(3,5-dichloropyrid-4-yl)-3-cyclopentyloxy-4-methoxybenzamide (1 gram,2.62 mmol) in phosphoryl chloride (15 milliliters, 161 mmol) and N,N-dimethylaniline (0.75 milliliters) was refluxed under nitrogen for 20hours. The mixture was cooled to room temperature, volatiles removedin-vacuo, and the brown residue azeotroped with toluene (3×20milliliters). The crude imino chloride was dissolved in toluene (15milliliters), an excess of benzylamine (2.57 milliliters, 23.58 mmol)was added in one portion and the mixture refluxed, under nitrogen, for 4hours. The mixture was cooled to room temperature, volatiles removedin-vacuo, and the residue dissolved in chloroform (100 milliliters) andwashed with water (2×50 milliliters). The combined organics were dried(Na₂ SO₄) and volatiles removed in-vacuo to yield a white solid. Themixture was purified by flash chromatography (SiO₂ ; ethyl acetate:hexane (1:9), followed by ethyl acetate: hexane (1:4)) to yield thetitle compound (624 milligrams, 50 %) as a white crystalline solid, m.p.129°-133° C.

δ_(H) (250 MHz; CDCl₃) 1.63 (8H, m, 4×CH₂), 3.78 (3H, s, OMe), 4.46 (1H,m, CH), 4.74 (2H, d, ARCH₂), 5.38 (1H, t, NH), 6.71 (2H, m, 2×ArH), 6.95(1H, dd, ArH), 7.38 (5H, m, 5×ArH), 8.20 (2H, s, 2×ArH).

EXAMPLE 6

Protocols for PDE III and PDE IV inhibition activity are set forthbelow:

Type III Phosphodiesterase Enzyme Isolation Protocol

The Type III PDE is isolated from human platelets using a proceduresimilar to that previously described by Weishaar, R. E., et al.,Biochem. Pharmacol., 35:787, 1986. Briefly, 1-2 units of platelets aresuspended in an equal volume of buffer (20 mM Tris-HCl, pH 7.5,containing 2 mM magnesium acetate, 1 mM dithiothreitol, and 5 mM Na₂EDTA). The proteinase inhibitor phenylmethyl-sulfonyl fluoride (PMSF) isalso included in this buffer at a final concentration of 200 μM. Thesuspension is homogenized using a polytron and the homogenatecentrifuged at 100,000×g for 60 minutes. This and all subsequentprocedures are performed at 0°-4° C. The supernatant is then filteredthrough four layers of gauze and applied to a DEAE-Trisacryl M column,previously equilibrated with buffer B (20 mM Tris-HCl, pH 7.5,containing 1 mM magnesium acetate, 1 mM dithiothreitol and 200 μM PMSF).After application of the sample, the column is washed with several bedvolumes of buffer B, after which the different forms of PDE are elutedfrom the column using two successive linear NaCl gradients (0.05-0.15M,300 milliliters total; 0.15-0.40M, 200 milliliters total). Fivemilliliter fractions are collected and assayed for cyclic AMP and cyclicGMP PDE activity. Fractions containing PDE III activity are pooled anddialyzed overnight against 4 liters of buffer B. The dialyzed PDE III isthen concentrated to 10% of the original volume, diluted to 50% withethylene glycol monoethyl ether and stored at -20° C. PDE III cantypically be retained for up to four weeks with little or no loss ofactivity.

Measuring Type III PDE Activity

Enzyme activity is assessed by measuring the hydrolysis of [³ H]-cyclicAMP, as described by Thompson, W. J., et al., Adv. Cyclic NucleotideRes. 10:69, 1979. The cyclic AMP concentration used in this assay is 0.2μM, which approximates to the K_(m) value. Protein concentration isadjusted to ensure that no more than 15% of the available substrate ishydrolyzed during the incubation period.

All test compounds are dissolved in dimethyl sulfoxide (finalconcentration of 2.5%). This concentration of dimethyl sulfoxideinhibits enzyme activity by approximately 10%.

Type IV Phosphodiesterase Enzyme Isolation Protocol

The Type IV PDE is isolated from bovine tracheal smooth muscle using aprocedure similar to that previously described by Silver, P. J., et al.Eur. J. Pharmacol. 150:85,1988. Briefly, smooth muscle from bovinetrachea is minced and homogenized using a polytron in 10 volumes of anextraction buffer containing 10 mM Tris-acetate (pH 7.5), 2 mM magnesiumchloride, 1 mM dithiothreitol and 2,000 units/milliliters of aprotinin.This and all subsequent procedures are performed at 0°-4° C. Thehomogenate is sonicated and then centrifuged at 48,000×g for 30 minutes.The resulting supernatant is applied to a DEAE Trisacryl M columnpreviously equilibrated with sodium acetate and dithiothreitol. Afterapplications of the sample, the column is washed with sodiumacetate/dithiothreitol, after which the different forms of PDE areeluted from the column using a linear Tris-HCl/NaCl gradient. Fractionscontaining Type IV PDE are collected, dialyzed and concentrated to 14%of the original volume. The concentrated fractions are diluted to 50%with ethylene glycol and stored at -20° C.

Measuring Type IV PDE Activity

Enzyme activity is assessed by measuring the hydrolysis of [³ H]-cyclicAMP, as described by Thompson, W. J., et al., Adv. Cyclic NucleotideRes. 10:69, 1979. The cyclic AMP concentration used in this assay is 0.2μM, which approximates the K_(m) value. Protein concentration isadjusted to ensure that no more than 15% of the available substrate ishydrolyzed during the incubation period.

All test compounds are dissolved in dimethyl sulfoxide (finalconcentration of 2.5%). This concentration of dimethyl sulfoxideinhibits enzyme activity by approximately 10%.

EXAMPLE 7

Following the above procedures, the PDE III and PDE IV inhibition forthe compounds of Examples 1-5, and rolipram were tested and compared.The results are shown in the Table below:

                  TABLE                                                           ______________________________________                                        IC.sub.50 (μM)                                                             Compound PDE III ACTIVITY                                                                             PDE IV ACTIVITY                                       ______________________________________                                        Example 1                                                                              >1000          2.2                                                   Example 2                                                                              >1000          2.8                                                   Example 3                                                                              89.5           1.8                                                   Example 4                                                                              205.4          3.2                                                   Example 5                                                                              >1000          0.3                                                   Rolipram 790            2.8                                                   ______________________________________                                    

Thus, it can be seen from the foregoing that compounds prepared inaccordance with the present invention have high levels of PDE IVinhibition while, at the same time relatively low levels of PDE IIIinhibition.

While the invention has been illustrated with respect to the productionand use of a particular compound, it is apparent that variations andmodifications of the invention can be made without departing from thespirit or scope of the invention.

What is claimed is:
 1. A compound of the formula: ##STR9## wherein: X₁ and X₂ may be the same or different and each is O or S;R₁ is selected from the group consisting of cycloalkyl and cycloalkyl-alkyl groups containing from 3 to 10 carbon atoms in the cycloalkyl moiety; R₂ is R₁ or CH₃ ; R₃ is hydrogen, halogen, or a saturated or unsaturated straight-chain or branched C₁₋₁₂ alkyl group, a cycloalkyl or cycloalkyl-alkyl groups containing from 3 to 7 carbon atoms in the cycloalkyl moiety; Z is a linkage selected from --CH₂ CONH-- and --CH₂ NHCO--; and R₄ is a phenyl or benzyl which may be unsubstituted or substituted with one or more halogen atoms, alkyl groups, hydroxyl groups, cyano groups, carboxyl groups, alkoxy groups, alkoxycarbonyl, amido, carboxamido, substituted or unsubstituted amino groups, cycloalkyl and cycloalkyl-alkyl groups containing from 3 to 10 carbon atoms in the cycloalkyl moiety, aryl or aralkyl groups preferably containing from about 6 to about 10 carbon atoms, or heterocyclic groups containing nitrogen, oxygen or sulfur in the ring; said alkyl, alkoxy, cycloalkyl, cycloalkyl-alkyl, aryl, and aryl-alkyl groups being saturated or unsaturated, unsubstituted or substituted by halogen atoms, hydroxyl groups, cyano groups, carboxyl groups, alkoxy groups, alkoxycarbonyl, carboxamido or substituted or unsubstituted amino groups, or one or more lower alkyl groups having from 1 to 3 carbon atoms;provided that R₄ cannot be substituted with more than one methoxy group.
 2. The compound of claim 1, wherein R₁ is a cycloalkyl of 3-6 carbon atoms, said cycloalkyl may be substituted by one or more alkyl groups or by one or more halogens, R₂ is hydrogen, or C₁₋₁₂ alkyl, and wherein R₃ is hydrogen, lower alkyl or halogen.
 3. The compound of claim 2 wherein R₁ is cycloalkyl optionally substituted by one or more halogens.
 4. The compound of claim 1 wherein R₂ is methyl or and wherein R₁ is cyclopentyl optionally substituted by R₅ as shown in the following structural formula: ##STR10## wherein R₅ is hydrogen or a saturated or unsaturated straight-chain lower alkyl group containing from about 1 to about 6 carbon atoms, unsubstituted or substituted with one or more halogen atoms, hydroxyl groups, cyano groups, nitro groups, carboxyl groups, alkoxy groups, alkoxycarbonyl, carboxamido or substituted or unsubstituted amino groups.
 5. The compound of claim 2 wherein Z is a linkage selected from the group consisting of --CH₂ CONH--, --CH₂ NHCO--.
 6. The compound of claim 2, wherein X₁ and X₂ are O.
 7. The compound of claim 2 wherein R₄ is an unsubstituted or substituted phenyl or benzyl.
 8. The compound of claim 6 wherein R₄ is a substituted phenyl having one of the following structures: ##STR11## wherein R₆ is an unsubstituted or substituted lower alkyl.
 9. The compound of claim 1, selected from the group consisting of:N-(3-Cyclopentyloxy-4-methoxyphenyl-acetyl)-2-allyloxy-5-chloroaniline; and N-(3-Cyclopentyloxy-4-methoxyphenyl-acetyl)-2-hydroxy-3-allyl-5-chloroaniline.
 10. A method of effecting selective PDE IV inhibition to a patient requiring the same, comprising administering an effective amount of the compound of claim
 1. 11. The method of claim 10, wherein said compound is selected from the group consisting of:N-(3-Cyclopentyloxy-4-methoxyphenyl-acetyl)-2-allyloxy-5-chloroaniline; and N-(3-Cyclopentyloxy-4-methoxyphenyl-acetyl)-2-hydroxy-3-allyl-5-chloroaniline.
 12. A pharmaceutical composition comprising the compound of claim
 1. 13. The pharmaceutical composition of claim 12, wherein said compound is selected from the group consisting of:N-(3-Cyclopentyloxy-4-methoxyphenyl-acetyl)-2-allyloxy-5-chloroaniline; and N-(3-Cyclopentyloxy-4-methoxyphenyl-acetyl)-2-hydroxy-3-allyl-5-chloroaniline.
 14. A method of treating a mammal suffering from a disease state selected from the group consisting of asthma, allergies, inflammation, depression, dementia, atopic diseases, rhinitis and disease states associated with abnormally high physiological levels of cytokine, comprising administering an effective amount of the compound of claim
 1. 15. The method of claim 14, wherein said compound is selected from the group consisting of:N-(3 -Cyclopentyloxy-4-methoxyphenyl-acetyl)-2-allyloxy-5-chloroaniline; and N-(3-Cyclopentyloxy-4-methoxyphenyl-acetyl)-2-hydroxy-3-allyl-5-chloroaniline. 